Particle-removing apparatus for a semiconductor device manufacturing apparatus and method of removing particles

ABSTRACT

In a semiconductor device manufacturing apparatus that processing a substrate by applying a voltage to a gas to create a plasma, positively charged particles are trapped or guided at the instant that the cathode voltage is stopped, by an electrode to which is imparted a negative voltage, so as to prevent particles reaching the substrate.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.09/290,636 filed on Apr. 12, 1990 now U.S. Pat. No. 6,184,489.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a particle-removing apparatus for asemiconductor device manufacturing apparatus and to a method of removingparticles, and more specifically it relates to a particle-removingapparatus that prevents the falling of particles that are generatedduring a process onto a wafer, and to a method for removing particles.

2. Description of the Related Art

Particles that are generated in the process of manufacturing asemiconductor device, and in particular in a process that makes use ofplasma, are a cause of reduced yield and a deterioration of uptime.These particles can be caused by the peeling off of substances that havebeen deposited within the process equipment by reactions and by growthof substances generated by reaction within the plasma. To prevent thefalling of these particles onto a substrate, as described in theJapanese Unexamined Patent Publications (KOKAI) No. 5-29272 and No.7-58033, there has been a proposal of an apparatus in which thesubstrate is covered after a process is completed.

FIG. 9(a) is a drawing that shows a plasma etching apparatus of thepast, in which the reference numeral 2100 denotes a processing chamber,inside which are provided an upper processing electrode 2200 and a lowerprocessing electrode 2300, the upper processing electrode 2200 beinggrounded, and a high-frequency power supply 2400 being connected to thelower processing electrode 2300.

Above the lower processing electrode 2300 there is provided anelectrostatic chuck electrode 2700, which is insulated by means of aninsulator 1900, a voltage being applied to this electrostatic chuckelectrode 2700 from a power supply 2600, so as to hold a semiconductorsubstrate 3000. The processing chamber 2100 is provided with an intakeport 3100 for processing gas and an exhaust port 3200. A cover 3600 isprovided so that particles do not fall onto the semiconductor substrate3000.

FIG. 9(b) illustrates the general equipment operation cycle of a plasmaetching process in a semiconductor device manufacturing process.

This process is for the case of a cycle in which a single substrate isprocessed. The substrate 3000, which is transported from a transportingport 3800, is transported to within the processing chamber 2100, atwhich point the process gas is introduced from the process gas intakeport 3100. When the pressure within the processing chamber 2100 reachesa prescribed value, a high-frequency voltage is applied from the powersupply 2400, so as to generated a plasma that etches the substrate 3000.Simultaneously with the above, the substrate 3000 is held by theelectrostatic chuck. After completion of the etching, the supply of thehigh-frequency voltage, the supply of the process gas, and theelectrostatic chuck are all stopped. After several seconds, an inert gasthat does not contribute to etching is supplied for a prescribed amountof time in order to quickly purge the chamber of the process gas. Thesubstrate 3000, after completion of this processing, is transported tooutside the processing chamber 2100 from the transporting port 3800.

In an apparatus of the past as described above, in order to preventparticles from falling onto the substrate 3000, the cover 3600 isprovided over the substrate 3000. According to an experiment by theinventor, however, in a semiconductor device manufacturing process thatuses plasma, the timing of the falling of particles onto a substrate wasshown to be intimately connected with the operating status of thesemiconductor device manufacturing apparatus. Specifically, in theabove-noted publications of the past, there was absolutely noconsideration given to the timing of the covering of the substrate, thisrepresenting a major problem with regard to not being able to preventthe attachment of particles to the substrate.

Accordingly, it is an object of the present invention to improve overthe above-noted drawback in the prior art, in particular by providing anovel particle-removing apparatus of a semiconductor devicemanufacturing apparatus and a method of removing particles whereby, bycontrolling the timing of the covering by a cover provided over thesubstrate in accordance with the processing condition of the substrate,the attachment of particles that are generated within the manufacturingapparatus during a process that uses plasma to the substrate isprevented.

It is another object of the present invention to provide novelparticle-removing apparatus of a semiconductor device particle andmethod of removing particles whereby, by making use of thecharacteristic that particles are positively charged, attachment of theparticles to the substrate is prevented without the use of a cover orthe like.

SUMMARY OF THE INVENTION

In order to achieve the above-noted object, the present invention adoptsthe following basic technical constitution.

Specifically, a first aspect of a particle-removing apparatus of asemiconductor device manufacturing apparatus according to the presentinvention is a particle-removing apparatus in which a high-frequencyvoltage is applied between an upper electrode and a lower electrode soas to generate a plasma within a processing chamber that processes asubstrate located in the processing chamber, in which is provided acover that covers the substrate, the substrate being covered by closingthis cover, so as to prevent the attachment of particles within theprocessing chamber to the substrate, this particle-removing apparatusbeing provided with a first control means for controlling the timing ofthe drive of the above-noted cover, this control means performingcontrol so as to change the cover from the opened condition to theclosed condition immediately before stopping the application of thehigh-frequency voltage.

In a second aspect of a particle-removing apparatus according to thepresent invention, control is performed so as to change the above-notedcover from the closed condition to the opened condition insynchronization with a tranport operation of a substrate-transportingapparatus that is provided in the semiconductor device manufacturingapparatus.

In a third aspect of a particle-removing apparatus according to thepresent invention, the timing of control of changing the cover from theclosed condition to the opened condition is immediately beforetransporting the substrate after completion of processing to outside theprocessing chamber.

In a fourth aspect of a particle-removing apparatus according to thepresent invention, the timing of control of changing the cover from theclosed condition to the opened condition is immediately aftertransporting the substrate after completion of processing to outside theprocessing chamber.

In a fifth aspect of a particle-removing apparatus according to thepresent invention, the timing of the control of changing the cover fromthe closed condition to the opened condition is immediately before theapplication of the high-frequency voltage.

In a sixth aspect of a particle-removing apparatus according to thepresent invention, in addition to imparting a potential to theabove-noted cover, a second control means, for controlling the timing ofapplication of the potential to the cover, is provided, this secondcontrol means performing control so that the potential is imparted tothe cover minimally from immediately before the stopping of applicationof the high-frequency voltage to several seconds after the starting ofintroduction of a purging gas.

In a seventh aspect of a particle-removing apparatus according to thepresent invention, the above-noted potential is imparted minimally untilimmediately before the introduction of the purging gas.

In an eighth aspect of a particle-removing apparatus according to thepresent invention, the above-noted potential is imparted until the timeat which the substrate is transported to outside the processing chamber.

In a ninth aspect of a particle-removing apparatus according to thepresent invention, the above-noted potential either is equivalent to aself-bias potential that appears on the lower electrode of theprocessing electrodes or has the same polarity as and a larger absolutevalue than the above-noted self-bias potential.

In a tenth aspect of a particle-removing apparatus according to thepresent invention, the above-noted potential is a potential that isequivalent to the potential on the lower electrode of the processingelectrodes.

A first aspect of a particle-removing method according to the presentinvention is a particle-removing method in a semiconductor devicemanufacturing apparatus in which a high-frequency voltage is appliedbetween an upper electrode and a lower electrode so as to generate aplasma within a processing chamber that processes a substrate located inthe processing chamber, in which is provided a cover that covers thesubstrate, the substrate being covered by closing this cover, so as toprevent the attachment of particles within the processing chamber to thesubstrate, this particle-removing method performing control so as tochange the cover from the opened condition to the closed conditionimmediately before stopping the application of the high-frequencyvoltage.

In a second aspect of a particle-removing method according to thepresent invention, control is performed so as to change the above-notedcover from the closed condition to the opened condition insynchronization with a transport operation of a substrate transportapparatus that is provided in the semiconductor device manufacturingapparatus.

A third aspect of a particle-removing method according to the presentinvention is a particle-removing method apparatus in a semiconductordevice manufacturing apparatus in which a high-frequency voltage isapplied between an upper electrode and a lower electrode so as togenerate a plasma within a processing chamber that processes a substratelocated in the processing chamber, in which is provided a cover thatcovers the substrate, the substrate being covered by closing this cover,so as to prevent the attachment of particles within the processingchamber to the substrate, this particle-removing method having a firststep of changing the cover from the opened condition to the closedcondition, a second step of stopping the application of thehigh-frequency voltage immediately after the cover is placed in theclosed condition, and a third step of imparting a potential to theabove-noted cover.

An eleventh aspect of a particle-removing apparatus of a semiconductordevice manufacturing apparatus according to the present invention is aparticle-removing apparatus in a semiconductor device manufacturingapparatus that has an etching processing chamber, a pair of processingelectrodes formed by an upper electrode and a lower electrode, which areinstalled within the processing chamber, and a susceptor that holds asubstrate to be processed onto the top of the above-noted lowerelectrode, a processing gas being introduced into the etching processingchamber and a prescribed voltage being applied to the above-notedprocessing electrodes, so as to generate a plasma thereof, therebyprocessing the substrate on the above-noted susceptor, thisparticle-removing apparatus being provided with a particle-removingelectrode for the purpose of removing particles inside the processingchamber, a negative voltage being applied to this particle-removingelectrode, thereby causing removal of charged particles in theprocessing chamber.

In a twelfth aspect of a particle-removing apparatus according to thepresent invention, the above-noted particle-removing electrode isprovided between the upper electrode and the lower electrode.

In a thirteenth aspect of a particle-removing apparatus according to thepresent invention, an exhaust port is provided on a side wall of theetching processing chamber in the region in which the particle-removingelectrode is provided.

In a fourteenth aspect of a particle-removing apparatus according to thepresent invention, the particle-removing electrode is provided over theabove-noted lower electrode, in a manner so as to surround thesubstrate.

In a fifteenth aspect of a particle-removing apparatus according to thepresent invention, the particle-removing electrode is provided betweenthe processing electrodes and a processing chamber side wall.

In a sixteenth aspect of a particle-removing apparatus according to thepresent invention, the particle-removing electrode is anattachment-preventing plate that prevents attachment of sediments onto awall surface of the processing chamber.

In a seventeenth aspect of a particle-removing apparatus according tothe present invention, the particle-removing electrode is providedeither within a gas intake or in the region of a gas exhaust port of theetching processing chamber.

An eighteenth aspect of a particle-removing apparatus of a semiconductordevice manufacturing apparatus according to the present invention is aparticle-removing apparatus in a semiconductor device manufacturingapparatus that has an etching processing chamber, a pair of processingelectrodes formed by an upper electrode and a lower electrode, which areinstalled within the processing chamber, and a susceptor that holds asubstrate to be processed onto the top of the above-noted lowerelectrode, a processing gas being introduced into the etching processingchamber and a prescribed voltage being applied to the above-notedprocessing electrodes, so as to generate a plasma of the gas, therebyprocessing the substrate on the susceptor, this particle-removingapparatus having a gas exhaust port of the processing chamber that isformed by an electrically conductive material, to which a negativevoltage is applied so as to remove charged particles from within theprocessing chamber.

A nineteenth aspect of a particle-removing apparatus of a semiconductordevice manufacturing apparatus according to the present invention is aparticle-removing apparatus in a semiconductor device manufacturingapparatus that has an etching processing chamber, a pair of processingelectrodes formed by an upper electrode and a lower electrode, which areinstalled within the processing chamber, and a susceptor that holds asubstrate to be processed onto the top of the above-noted lowerelectrode, a processing gas being introduced into the etching processingchamber and a prescribed voltage being applied to the above-notedprocessing electrodes, so as to generate a plasma of the gas, therebyprocessing the substrate on the susceptor, this particle-removingapparatus being provided, between the upper electrode and the lowerelectrode, with an electrically conductive grid-configured material forthe purpose of removing particles, a negative voltage being applied tothe grid-configured material, so as to remove charged particles fromwithin the processing chamber.

A twentieth aspect of a particle-removing apparatus of a semiconductordevice manufacturing apparatus according to the present invention is aparticle-removing apparatus in a semiconductor device manufacturingapparatus that has an etching processing chamber, a pair of processingelectrodes formed by an upper electrode and a lower electrode, which areinstalled within the processing chamber, and a susceptor that holds asubstrate to be processed onto the top of the above-noted lowerelectrode, a processing gas being introduced into the etching processingchamber and a prescribed voltage being applied to the above-notedprocessing electrodes, so as to generate a plasma of the gas, therebyprocessing the substrate on the susceptor, this particle-removingapparatus being provided, in the region of substrate, with aparticle-removing electrode for the purpose of removing particles, anegative voltage having an absolute value that is greater than theself-bias voltage of the above-noted lower electrode being applied tothis particle-removing electrode, so as to prevent the falling ofparticles within the processing chamber onto the substrate.

A twenty-first aspect of a particle-removing apparatus of asemiconductor device manufacturing apparatus according to the presentinvention is a particle-removing apparatus in a semiconductor devicemanufacturing apparatus that has an etching processing chamber, a pairof processing electrodes formed by an upper electrode and a lowerelectrode, which are installed within the processing chamber, and asusceptor that holds a substrate to be processed onto the top of theabove-noted lower electrode, a processing gas being introduced into theetching processing chamber and a prescribed voltage being applied to theabove-noted processing electrodes, so as to generate a plasma of thegas, thereby processing the substrate on the susceptor, a prescribedbias being added to the voltage that is applied to the lower electrode,this being varied in the same manner as the self-bias voltage, therebycausing charged particles to be directed toward the lower electrode, soas to prevent these particles from falling onto the above-notedsubstrate.

In a twenty-second aspect of a particle-removing apparatus according tothe present invention, a laser apparatus is provided for the purpose ofdetecting the occurrence of the above-noted particles, light from thislaser apparatus being shined in an area surrounding the above-notedupper electrode so as to detect the presence of particles inside theprocessing chamber, and a third control means being further provided forthe purpose of applying a negative voltage to the particle-removingelectrode, based on the results of this detection.

A twenth-third aspect of a particle-removing apparatus of asemiconductor device manufacturing apparatus according to the presentinvention is a particle-removing apparatus in a semiconductor devicemanufacturing apparatus that has an etching processing chamber, a pairof processing electrodes formed by an upper electrode and a lowerelectrode, which are installed within the processing chamber, and asusceptor that holds a substrate to be processed onto the top of theabove-noted lower electrode, a processing gas being introduced into theetching processing chamber and a prescribed voltage being applied to theabove-noted processing electrodes, so as to generate a plasma thereof,thereby processing the substrate on the above-noted susceptor, thisparticle-removing apparatus being provided with a electricallyconductive planar particle-removing electrode for the purpose ofremoving particles inside the processing chamber, a negative voltagebeing applied to this particle-removing electrode, thereby causingremoval of charged particles in the processing chamber.

In a twenty-fourth aspect of a particle-removing apparatus according tothe present invention, the above-noted particle-removing electrode is inthe form of a grid-configured electrically conductive electrode.

In a twenty-fifth aspect of a particle-removing apparatus according tothe present invention, the above-noted negative voltage is applied afterthe completion of etching.

In a twenty-sixth aspect of a particle-removing apparatus according tothe present invention, the above-noted negative voltage is appliedduring transport of the substrate.

A fourth aspect of a particle-removing method of a semiconductor devicemanufacturing apparatus according to the present invention is aparticle-removing method for a semiconductor device manufacturingapparatus that has an etching processing chamber, a pair of processingelectrodes formed by an upper electrode and a lower electrode, which areinstalled within the processing chamber, and a susceptor that holds asubstrate to be processed onto the top of the above-noted lowerelectrode, a processing gas being introduced into the etching processingchamber, a prescribed voltage being applied to the above-notedprocessing electrodes, so as to generate a plasma of the gas, therebyprocessing the substrate on the susceptor, and a particle-removingelectrode for the purpose of removing particles being provided insidethe processing chamber, whereby, after completion of the etching of thesubstrate, a negative voltage is applied to the particle-removingelectrode, so that charged particles inside the processing chamber areguided to this particle-removing electrode and caused to be attached tothe particle-removing electrode, thereby preventing the particles frombecoming attached to the substrate.

In a fifth aspect of a particle-removing method according to the presentinvention, after the application of the negative voltage to theparticle-removing electrode, the etching gas in the processing chamberis exhausted.

A sixth aspect of a particle-removing method of a semiconductor devicemanufacturing apparatus according to the present invention is aparticle-removing method for a semiconductor device manufacturingapparatus that has an etching processing chamber, a pair of processingelectrodes formed by an upper electrode and a lower electrode, which areinstalled within the processing chamber, and a susceptor that holds asubstrate to be processed onto the top of the above-noted lowerelectrode, a processing gas being introduced into the etching processingchamber, and a prescribed voltage o being applied to the above-notedprocessing electrodes, so as to generate a plasma of the gas, therebyprocessing the substrate on the susceptor, wherein a gas exhaust port ofthe processing chamber is formed of an electrically conductive material,and a negative voltage is applied to this exhaust port, so as to guidecharged particles toward the gas exhaust port and simultaneously exhaustthe etching gas from within the processing chamber.

An seventh aspect of a particle-removing method of a semiconductordevice manufacturing apparatus according to the present invention is aparticle-removing method for a semiconductor device manufacturingapparatus that has an etching processing chamber, a pair of processingelectrodes formed by an upper electrode and a lower electrode, which areinstalled within the processing chamber, and a susceptor that holds asubstrate to be processed onto the top of the above-noted lowerelectrode, a processing gas being introduced into the etching processingchamber, and a prescribed voltage being applied to the above-notedprocessing electrodes, so as to generate a plasma of the gas, therebyprocessing the substrate on the susceptor, wherein by causing the sizeof the generated plasma to greatly extend beyond the substrate,particles inside the processing chamber are caused to fall along theperiphery of the plasma, so that they are prevented from becomingattached to the substrate.

A particle-removing apparatus for a semiconductor device manufacturingapparatus according to the present invention is a particle-removingapparatus for a semiconductor device manufacturing apparatus in which ahigh-frequency voltage is applied between an upper electrode and a lowerelectrode to cause a plasma within the processing chamber so as toprocess a substrate therewithin, a cover that covers the substrate beingprovided, the substrate being covered by changing cover to the closedcondition, so as to prevent particles within the processing chamber frombecoming attached to the substrate, and a first control means thatcontrols the timing of the drive timing of the cover being alsoprovided, this first control means performing control so that the coveris changed from the opened condition to the closed condition immediatelybefore stopping the application of the above-noted high-frequencyvoltage applied between an upper electrode and a lower electrode, and sothat the cover is changed from the closed condition to the openedcondition in synchronization with a transporting operation of asubstrate transport apparatus provided in the semiconductor devicemanufacturing apparatus.

Therefore, by driving the cover so as to cover the substrate immediatelybefore particles are generated, the attachment of the particles to thesubstrate is prevented.

Additionally, by imparting an appropriate potential to the cover, thecover has a dust-collecting action, enabling even more effectiveprevention of attachment of the particles to the substrate.

Next, yet another aspect of an embodiment of the present invention willbe described.

FIG. 21 is a photograph of the behavior of particles in a plasma,inserted into a schematic representation of the apparatus. The rightedge of the drawing corresponds to the region at the center of theprocess apparatus, and the left edge corresponds to the region of thewall of the process apparatus.

Particles are trapped in a sheath region in proximity to the upperelectrode as shown in FIG. 21 and, at the instant the plasma collapses,so that the particles in the region of the upper electrode fly towardthe outer walls by the potential of the afterglow plasma. In the centerpart of the chamber, however, the particles fall downward around theoutside of the plasma, and in the region of the lower electrode, thisbeing the region of the wafer, it can be seen that the negativeself-bias potential causes the particles to fly towards the wafer.

From the above-noted results, the particles are seen to be positivelycharged, and the basis of the present invention is the use of this factto remove the particles using electrostatic induction.

FIG. 9(b) shows an example of the relationship between the number ofparticles that are generated in the etching apparatus during operation,and the operation condition of the apparatus at that time.

The apparatus that is shown in FIG. 9(a) is an etching apparatus of thepast that has flat parallel processing electrodes.

FIG. 9(b) is a representation of a cycle of processing one substrate.When the substrate is transported to inside the processing chamber fromthe transporting port, the processing gas is supplied and, when thepressure within the processing chamber reaches a prescribed value, ahigh-frequency voltage is applied, so as to generate a plasma, therebycausing etching of the substrate. When this is done, the substrate isheld by the susceptor on the top of the lower electrode.

After completion of the above-noted etching, the supply of thehigh-frequency voltage, the supply of the process gas, and theelectrostatic chucking are all stopped. After several seconds, an inertgas that does not contribute to etching is supplied for a prescribedamount of time in order to quickly purge the chamber of the process gas,this causing the pressure within the processing chamber to rise.

The substrate, after completion of this processing, is transported tooutside the processing chamber from the transporting port. In thedrawing, the number of particles P represented by the ellipses is theresult of introducing the light from a laser into the region over thesubstrate in the processing chamber, and using a CCD camera tophotograph the light scattered by particles that traverse this laserlight, a signal that indicates the operating condition of the etchingapparatus being simultaneously captured. The number shown is theaccumulated number obtained from the processing of 25 substrates.

From FIG. 9(b), it is clear that the occurrence of particles P duringetching corresponds to the operating condition of the apparatus. Thatis, while there is almost no particle generation during etching, whenthe etching is completed, there is a time when a large number ofparticles are generated, and the frequency of generation of particles ishigh when the purging gas is introduced.

A detailed examination of the images obtained from the light scatteredby the particles revealed that the traces of particles at the time ofthe completion of the etching exhibit a tendency to be directed towardthe substrate, and a tendency to be directed toward the exhaust portwhen the purging gas is introduced.

From the above, it can be envisioned that because the high-frequencypower supply is stopped when the etching is completed, particles thatfloat during etching fall and, because the viscous flow of theprocessing gas is small, the particles fly toward the substrate, onwhich all of its electrical charge have not been removed.

It is further envisioned, however, that several seconds after thecompletion of etching, purging gas is introduced, the result being thatthe particles head toward the exhaust port with the purging gas.

In the present invention, the wafer is covered when the supply ofvoltage is stopped. Also, using the fact that the particles in theprocessing chamber are positively charged, by imparting a negativepotential to an electrically conductive plate or grid, the generatedparticles are trapped, or caused to migrate toward the exhaust port,thereby preventing them from reaching the substrate.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1a, 1 b are block diagrams that show a particle-removing apparatusof a semiconductor device manufacturing apparatus according to thepresent invention.

FIG. 2 is a drawing that shows the configuration of a particle-removingapparatus according to the present invention.

FIG. 3 is a drawing that shows the operational timing of a substratecover in the first embodiment of the present invention.

FIG. 4 is a drawing that shows the operational timing of a substratecover in the second embodiment of the present invention.

FIG. 5 is a drawing that shows the operational timing of a substratecover in the third embodiment of the present invention.

FIGS. 6a, 6 b are drawings that show the timing of the application of apotential to the substrate cover in the fourth embodiment of the presentinvention.

FIG. 7 is a drawing that shows the timing of the application of apotential to the substrate cover in the fifth embodiment of the presentinvention.

FIG. 8 is a drawing that shows the timing of the application of apotential to the substrate cover in the sixth embodiment of the presentinvention.

FIG. 9(a) is a drawing that shows the configuration of an etchingapparatus of the past, FIG. 9(b) is a drawing that shows therelationship between the operating condition of an etching apparatus andthe number of particles generated.

FIG. 10 is a drawing that shows the operational timing in a conventionaletching apparatus.

FIGS. 11a, 11 b are drawings that show the seventh embodiment of thepresent invention.

FIG. 12 is drawing that shows the eight embodiment of the presentinvention.

FIG. 13 is drawing that shows the ninth embodiment of the presentinvention.

FIG. 14 is drawing that shows the tenth embodiment of the presentinvention.

FIG. 15 is drawing that shows the eleventh embodiment of the presentinvention.

FIG. 16 is drawing that shows the twelfth embodiment of the presentinvention.

FIG. 17 is drawing that shows the thirteenth embodiment of the presentinvention.

FIG. 18 is drawing that shows the fourteenth embodiment of the presentinvention.

FIG. 19 is drawing that shows the fifteenth embodiment of the presentinvention.

FIG. 20 is drawing that shows the sixteenth embodiment of the presentinvention.

FIG. 21 is a photograph that show the movement of particles in a plasma.

FIG. 22 is a drawing that shows the operational timing of a substratecover in the seventeenth embodiment of the present invention.

FIG. 23 is a drawing that shows the operational timing of a substratecover in the eighteenth embodiment of the present invention.

FIG. 24 is a drawing that shows the operational timing of a substratecover in the nineteenth embodiment of the present invention.

FIG. 25 is a drawing that shows the timing of the application of apotential to the substrate cover in the twentieth embodiment of thepresent invention.

FIG. 26 is a drawing that shows the timing of the application of apotential to the substrate cover in the twenty-first embodiment of thepresent invention.

FIG. 27 is a drawing that shows the timing of the application of apotential to the substrate cover in the twenty-second embodiment of thepresent invention.

FIG. 28 is a cross-sectional view that shows the structure of a generalDC plasma processing apparatus.

FIG. 29 is a drawing that shows the twenty-third embodiment of thepresent invention.

FIG. 30 is a drawing that shows the twenty-fourth embodiment of thepresent invention.

FIG. 31 is a drawing that shows the twenty-fifth embodiment of thepresent invention.

FIG. 32 is a drawing that shows the twenty-sixth embodiment of thepresent invention.

FIG. 33 is a drawing that shows the twenty-seventh embodiment of thepresent invention.

FIG. 34 is a drawing that shows the twenty-eight embodiment of thepresent invention.

FIG. 35 is a drawing that shows the twenty-ninth embodiment of thepresent invention.

FIG. 36 is a drawing that shows the thirtieth embodiment of the presentinvention.

FIG. 37 is a drawing that shows the thirty-first embodiment of thepresent invention.

FIG. 38 is a drawing that shows the thirty-second embodiment of thepresent invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Embodiments of the present invention are described below in detail, withreference being made to the relevant accompanying drawings.

FIG. 1(a) is a block diagram that show the structure of an embodiment ofthe present invention, this being a semiconductor device manufacturingapparatus.

This block diagrams shows a semiconductor device manufacturing apparatus4000 in which a high-frequency voltage is applied between an upperelectrode 2200 and a lower electrode 2300, so as to generate a plasmainside a processing chamber 3100, thereby processing a substrate 3000, acover 3600 being provided which covers the substrate, this cover 3600being closed to cover the substrate 3000, thereby preventing theattachment of particles to the substrate 3000.

In the above-noted apparatus, there is provided a first control means200, which controls the drive timing of the cover 3600, this controlmeans 200 performing control so that the cover is changed from theopened condition to the closed condition immediately before stopping theapplication of the high-frequency voltage, and also performing controlso that the cover 3600 is changed from the closed condition to theopened condition in synchronization with a transport operation of asubstrate transport apparatus 1600, which is provided in thesemiconductor device manufacturing apparatus 4000.

FIG. 1(b) is a block diagram that shows the overall configuration aplasma etching apparatus according to the present invention, this beingformed by a driving apparatus 400 for the cover 3600, an etching gassupply apparatus 1200 for supplying etching gas to inside the processingchamber 2100, a purging gas supply apparatus 1300 for supplying purginggas to inside the processing chamber so as to exhaust the etching gastherefrom, a vacuum adjustment apparatus 1400 for the purpose ofadjusting the degree of vacuum inside the processing chamber, anexhausting apparatus 1500 for exhausting the gas from within theprocessing chamber, a substrate transporting apparatus 1600 fortransporting the substrate, a high-frequency (less than 10 GHz) powersupply 2400 for generating a plasma, and a controller 1700, a DC powersupply 2600 for the electrostatic chuck that holds the substrate,controller 1700, such as a microcomputer or sequencer or the like, whichcontrols a driving apparatus 400, an etching gas supply apparatus 1200,a purging gas supply apparatus 1300, a vacuum adjustment apparatus 1400,an exhausting apparatus 1500, a substrate transporting apparatus 1600, ahigh-frequency power supply 2400, and the configuration being such thatthe substrate 3000 is subjected to the prescribed processing.

In the above-noted apparatus 4000, the first control means 200 and asecond control means 300 are included within the controller 1700. Thus,the semiconductor device manufacturing apparatus used in the presentinvention, with the exception of the control of the cover 3600, has thesame configuration as in the past.

FIG. 9(b) is a drawing that shows the relationship between the number ofparticles P that are generated during plasma etching and the operatingcondition of the etching apparatus.

In this drawing, the number of particles P that are represented by theellipses is the result of introducing the light from a laser into theregion over the substrate in the processing chamber, and using a CCDcamera to photograph the light scattered by particles that traverse thislaser light, a signal that indicates the operating condition of theetching apparatus being simultaneously captured, this number being theaccumulated value obtained by processing 25 substrates. The generationof particles P during etching has a clear relationship to the operatingcondition of the apparatus. That is, while there is almost no particlegeneration during etching, when the etching is completed, there is atime when a large number of particles are generated, and the frequencyof generation of particles is high when the purging gas is introduced.

If a detailed examination is made of the images obtained from the lightscattered by the particles, it is seen that the traces of particles atthe time of the completion of the etching exhibit a tendency to bedirected toward the substrate, and a tendency to be directed toward theexhaust port when the purging gas is introduced.

From the above, it can be envisioned that because the high-frequencypower supply is stopped when the etching is completed, particles thatfloat during etching fall and, because the viscous flow of theprocessing gas is small, the particles fly toward the substrate, onwhich all of its electrical charge have not been removed. It is furtherenvisioned, however, that several seconds after the completion ofetching, purging gas is introduced, the result being that the particleshead toward the exhaust port with the purging gas.

The embodiments of the present invention to be described below wereinvented with the above-noted phenomenon as a basis.

The first to sixteenth embodiments of the present invention describedbelow all can be applied to an RF plasma CVD apparatus, an RF plasmaetching apparatus, and an RF plasma sputtering apparatus. Unlessspecifically indicated, the descriptions of the embodiments will be forthe case of application to an RF plasma etching apparatus. However, itshall be understood that these embodiments can be applied as well to theabove-noted other types of RF processing apparatuses.

First Embodiment

The flow of cover operation timing in the first embodiment of thepresent invention is shown in FIG. 3(a). At the time t1, immediatelybefore the stopping of the high-frequency voltage, the cover 3600 thatcovers the substrate 3000 is closed and, at the instant that thehigh-frequency voltage is stopped, particles that fall toward thesubstrate 3000 are caught by the cover 3600. The cover 3600 remainsclosed during the introduction of the purging gas, at which time thereis a high frequency of generation of particles and, after theintroduction of the purging gas is stopped, at the time t2, immediatelybefore the processed substrate is transported to outside the processingchamber 2100, the cover is opened. Thus, during the period of time whenmany particles P would fall onto the substrate, because the cover 3600is in the closed condition, thereby reliably covering the substrate3000, the attachment of the particles onto the substrate 3000 isprevented.

The shape of the cover can be that of a single sheet, or that of aplurality of blades, such as those of a camera shutter. In contrast tothe prior art, the present invention is not limited in application to aplasma etching apparatus, and can be applied as well to otherapparatuses, such as a plasma CVD apparatus, which uses plasma toperform processing.

As shown in FIG. 3(b), the timing of the opening of the cover can beestablished at time t21, which is immediately after the transport of theprocessed substrate to outside the processing chamber 2100.

Second Embodiment

The flow of cover operation timing in the second embodiment of thepresent invention is shown in FIG. 4. At the time t1, immediately beforethe stopping of the high-frequency voltage, the cover 3600 that coversthe substrate 3000 is closed and, at the instant that the high-frequencyvoltage is stopped, particles that fall toward the substrate 3000 arecaught by the cover 3600. After the processed substrate 3000 istransported to outside the processing chamber 2100, at the time t3,immediately before the next substrate is transported into the processingchamber, the cover 3600 is opened. Thus, by operating the cover 3600 inthis manner, attachment of particles that fall onto the substrate isprevented.

Third Embodiment

The flow of cover operation timing in the third embodiment of thepresent invention is shown in FIG. 5. At the time t4, immediately beforethe application of the high-frequency voltage, the cover 3600 thatcovers the substrate 3000 is opened and, at time t1, immediately beforethe high-frequency voltage is stopped, the cover is closed. By closingthe cover when etching is not being performed, particles occurringbecause of peeling from the upper electrode 2200 or from the insidewalls of the processing chamber 2000 are caught by the cover, therebypreventing the attachment of these particles to the substrate.

Furthermore, in addition to the above-noted configurations, it ispossible to use a configuration in which a detection means is providedthat detects that the cover has been placed in the closed condition, theresult of the detection by this detection means being used to turn offthe high-frequency power supply 2400.

Fourth Embodiment

The flow of cover operation timing in the fourth embodiment of thepresent invention is shown in FIG. 6(a). In addition to the first to thethird embodiments, during the period of time from t5, immediately beforethe stopping of the application of the high-frequency voltage, to thetime t6, several seconds after the start of the introduction of thepurging gas, a potential is imparted to the cover 3600. Because evenimmediately after the stopping of the application of the high-frequencyvoltage, particles fall toward the charged substrate that has a residualcharge from the electrostatic chuck, this cover potential can beselected as a value that is either equivalent to the self-bias potentialof the lower electrode 2300, or as a potential with the same polarity asand a larger absolute value than the above-noted self-bias potential.Particles that are generated immediately after the stopping ofapplication of the high-frequency voltage fall toward the cover and areattracted to the cover 3600. Particles that are generated after theintroduction of the purging gas follow the flow of the purging gas, andfall toward the exhaust port, so that they do not become attached to thesubstrate.

The material of the cover 3600 can be the same conductive material asthe processing chamber 2100 inner wall, this being for example analuminum alloy and, to reduce the number of particles that aregenerated, it can also have a metallic surface that is covered withaluminum oxide or silicon oxide.

It is also possible, as shown in FIG. 6(b), to impart the potential attime t61, immediately before the introduction of the purging gas.

Fifth Embodiment

The flow of cover operation timing in the fifth embodiment of thepresent invention is shown in FIG. 7.

In the cases of the second and third embodiments of the presentinvention, as shown in FIG. 4 and FIG. 5, it is possible to impart apotential to the cover from the time t7, at which the application of thehigh-frequency voltage is stopped, until time t8, at which point theprocessed substrate has been completely transported to outside theprocessing chamber, this cover potential being selectable either asequivalent to the self-bias potential of the lower electrode 2300, or asa potential with the same polarity as and a larger absolute value thanthe above-noted self-bias potential. Particles that are generated in theperiod from the time immediately after the stopping of application ofthe high-frequency voltage to the time the transporting port opens arecollected by the cover, and therefore do not become attached to thesubstrate.

Sixth Embodiment

The flow of cover operation timing in the sixth embodiment of thepresent invention is shown in FIG. 8.

In the cases of the second and third embodiments of the presentinvention, as shown in FIG. 4 and FIG. 5, it is possible to impart apotential to the cover, from the time that the cover is started to beclosed until the time the cover is opened. By making the cover 3600 thesame potential as the lower processing electrode 2300 during theapplication of the high-frequency voltage, there is no discharge betweenthe substrate 3000 and the cover 3600, thereby enabling prevention ofdamage to the substrate and the generation of particles between thecover and the substrate.

Then, after the application of the high-frequency voltage is stopped,the cover potential is either made equivalent to the self-biaspotential, or a potential that has the same polarity as and an absolutevalue that is greater than the self-bias value.

It is also possible to apply this embodiment to the first embodiment.

Seventh Embodiment

FIG. 10 shows one typical operating cycle of an etching apparatusgenerally used in a semiconductor device plant.

Etching is performed by introducing a highly reactive processing gassuch as chlorine into the processing chamber from a spraying plate thatalso serves as the upper processing electrode that is in opposition tothe substrate and, when the pressure reaches a prescribed pressure,applying a voltage between the electrodes, so as to generate a plasma ofthe processing gas.

When etching is completed, the application of the high-frequency voltageand the introduction of the processing gas are stopped simultaneouslyand, after several seconds have elapsed, a purging gas having a lowreactivity, such as a halogen gas, is introduced.

In an etching apparatus of the seventh embodiment of the presentinvention, as shown in FIG. 11, the process gas supply is stopped whenthe etching is completed. When this is done, it is known that theparticles have a positive charge and, by making use of this phenomenon,by imparting a negative potential to an electrically conductiveparticle-removing electrode 11 that is provided between the upperprocessing electrode 2200 and lower processing electrode 2300 inside theprocessing chamber 2100, particles are forcibly removed. As long asthere is no influence on the process, the particle-removing electrode 11can be any shape such as that of a sheet or grid.

The large number of falling particles that are generated at the instantthat the high-frequency voltage is stopped are trapped by theparticle-removing electrode 11, thereby preventing their reaching thesubstrate 3000.

It is also possible to adopt a configuration in which a power supplycontroller 420 and a negative power supply 410 are provided, whereby anegative potential is applied to the electrode 11 in synchronizationwith the completion of the etching.

Eighth Embodiment

FIG. 12 shows an etching apparatus into which a function has been builtto trap particles, using an attachment-prevention shield.

In a semiconductor device manufacturing apparatus, anattachment-prevention shield 12 is often used to prevent the attachmentof sediments that occur during processing onto the chamber walls.

These attachment-prevention shields 12 are provided between theprocessing electrodes 2200, 2300 and the side walls of the processingchamber 2100, and intentionally cause sediments to be deposited ontothese attachment-prevention shields 12, Andy replacing theattachment-prevention shields 12, it is possible to reduce the number oftimes the inside of the chamber needs to be cleaned.

The attachment-prevention shield 12 is often made of an electricallyconductive metal, the attachment-prevention shield 12 being keptelectrically insulated from the processing chamber, and when the etchingis completed the supply of processing gas is stopped and a negativepotential is imparted to the attachment-prevention shield 12.

The large number of positively charged falling particles that aregenerated at the instant that the high-frequency voltage is stopped arepulled in by the negative potential on the attachment-prevention shield12 and trapped and ultimately are trapped on the wall of theattachment-prevention shield 12, thereby preventing their reaching thesubstrate 3000.

Ninth Embodiment

FIG. 13 shows an etching apparatus into which a function has built totrap particles, using an electrically conductive grid 13.

Specifically, the grid 13 is provided between the processing electrodes2200, 2300 and the side walls of the processing chamber 2100, this grid13 being installed so that it is electrically insulated from theprocessing chamber and, when the etching is completed, the supply ofprocessing gas is stopped and a negative potential is imparted to thegrid 13.

The large number of positively charged particles that fall when thehigh-frequency voltage is stopped are pulled in by the negativepotential of the grid 13, and are ultimately trapped by this grid 13, sothat they are prevented from reaching the substrate.

Tenth Embodiment

FIG. 14 shows an etching apparatus in which a gas exhaust port 14 at thebottom of the processing chamber is formed of an electrically conductivematerial such as a metal, this gas exhaust port 14 being electricallyinsulated, so that particles are guided to the exhaust port and forciblyexhausted, the result being that the particles do not fall onto thesubstrate.

That is, when the supply of the processing gas is stopped at thecompletion of the etching, a negative potential is imparted to theexhaust port 14, the result being that the large number of positivelycharged particles that fall at the instant the high-frequency voltage isstopped are pulled in toward the exhaust port 14, which has a negativepotential, these particles being ultimately exhausted, so that they areprevented from reaching the substrate.

Eleventh Embodiment

FIG. 15 shows an etching apparatus in which an electrically conductivegrid 13 is provided in proximity to the gas exhaust port 14, this gridserving to trap particles.

Specifically, the grid 13 is installed in front of the exhaust port 14so that it is electrically insulated with respect to the chamber, thesupply of the processing gas being stopped and a negative potentialbeing imparted to the grid 13 when etching is completed.

The large number of positively charged particles that fall at theinstant the high-frequency voltage is stopped are pulled in toward thegrid 13 because of its negative potential and are ultimately trapped bythe grid 13 or exhausted from the exhaust port 14, so that they areprevented from reaching the substrate.

Twelfth Embodiment

FIG. 16 shows the twelfth embodiment of the present invention.

In this embodiment, the electrically conductive grid 13 is installedbetween the upper electrode 2200 and the lower electrode 2300, and isplaced in an electrically floating condition. By doing this, during theprocess, that is during discharge, the grid 13 tracks to the potentialof the plasma, so that it is in the floating condition.

After the process is completed, when a negative potential is imparted tothe grid 13, particles are pulled in toward the negative potential ofthe grid 13, thereby being prevented from reaching the substrate. Then,in this condition, the semiconductor substrate 3000 is transported.

Thirteenth Embodiment

FIG. 17 shows the thirteenth embodiment of the present invention.

In this embodiment, a plasma PZ is generated that is sufficiently largewith respect to the semiconductor substrate 3000. This plasma PZ isgenerated in accordance with the diameters of the upper electrode 2200and the lower electrode 2300 and, in the case of FIG. 17, this is aplasma that is generated to considerably outside the substrate 3000.

By doing this, so that the plasma PZ extends greatly beyond thesubstrate 3000, particles drop along the outer periphery of the plasmaPZ, thereby preventing them from falling onto the substrate 3000.

Fourteenth Embodiment

FIG. 18 shows the fourteenth embodiment of the present invention.

In this embodiment, a donut-shaped electrode 15 is installed over thelower electrode 2300 so as to surround the substrate 3000, a negativevoltage that has an absolute value that is greater than the self-biasvoltage being applied to the electrode 15, in which case the appliedvoltage can be a DC voltage.

The timing of the application of the above-noted voltage is the timethat the process is completed and the time that the plasma power supplyis turned off.

A negative bias is applied with respect to the voltage applied to thelower electrode 2300, which is the cathode electrode, and this is causedto vary in the same manner as the self-bias voltage.

By doing the above, positively charged particles are guided to theelectrode 15, thereby preventing them from falling onto the substrate3000.

Fifteenth Embodiment

FIG. 19 shows the fifteenth embodiment of the present invention.

In this embodiment, a laser apparatus is introduced for the purpose ofmonitoring the generation of particles. The location at which the laserlight is shined is the region under the anode electrode, this being theupper electrode 2200. By adopting this configuration, it is possible todetect particles at an early stage that are trapped in the region nearthe plasma sheath.

Then, after the particles are detected, a negative voltage is applied tothe electrode 15, so as to collect the particles, preventing them fromfalling onto the substrate 3000.

Sixteenth Embodiment

FIG. 20 shows the sixteenth embodiment of the present invention.

In this embodiment, a particle-removing electrode 15 is provided betweenthe upper electrode 2200 and the lower electrode 2300, and a gate valve17 is installed on a side wall of the processing chamber near theparticle-removing electrode 15, a vacuum pump or other such exhaustingapparatus being connected to the outside thereof. A provision is alsomade to apply a negative voltage to the electrode 15.

When the processing is completed and the voltage applied to the cathodeelectrode, which is the lower electrode 2300, is cut off, a negativevoltage is applied to the electrode 15. By doing this, particles arepulled toward the gate valve 17. When this occurs, the gate valve 17 issimultaneously opened, so that the particles are exhausted, therebypreventing the particle from falling onto the substrate 3000.

In FIG. 19, the reference numeral 450 denotes a third control means forthe purpose of applying a negative voltage to the particle-removingelectrode 15, based on the results of the detection of particles withinthe processing chamber.

All of the above-described first embodiment through sixteenth embodimentcan be applied in common to an RF plasma CVD apparatus, an RF plasmaetching apparatus, and an RF plasma puttering apparatus.

In contrast to the above, the seventeenth through thirty-secondembodiments to be described below can be applied in common to a DCplasma CVD apparatus, a DC plasma etching apparatus, and a DC plasmasputtering apparatus.

Seventeenth Embodiment

The flow of cover operation timing in the seventeenth embodiment of thepresent invention is shown in FIG. 22.

At the time t11, immediately before the stopping of the DC voltage, thecover 3600 that covers the substrate 3000 is closed and, at the instantthat the DC voltage is stopped, particles that fall toward the substrate3000 are caught by the cover 3600. The cover 3600 remains closed duringthe introduction of the purging gas, at which time there is a highfrequency of generation of particles and, after the introduction of thepurging gas is stopped, at the time t12, immediately before theprocessed substrate is transported to outside the processing chamber2100, the cover is opened. Thus, during the period of time when manyparticles P would fall onto the substrate, because the cover 3600 is inthe closed condition, thereby reliably covering the substrate 3000, theattachment of the particles P onto the substrate 3000 is prevented.

The shape of the cover can be that of a single sheet, or that of aplurality of blades, such as those of a camera shutter.

Eighteenth Embodiment

The flow of cover operation timing in the eighteenth embodiment of thepresent invention is shown in FIG. 23.

At the time t11, immediately before the stopping of the DC voltage, thecover 3600 that covers the substrate 3000 is closed and, at the instantthat the DC voltage is stopped, particles that fall toward the substrate3000 are caught by the cover 3600. After the processed substrate 3000 istransported to outside the processing chamber 2100, at the time t13,immediately before the next substrate is transported into the processingchamber, the cover 3600 is opened. Thus, by operating the cover in thismanner, attachment of particles that fall onto the substrate isprevented.

Nineteenth Embodiment

The flow of cover operation timing in the nineteenth embodiment of thepresent invention is shown in FIG. 24.

At the time t14, immediately before the application of the DC voltage,the cover that covers the substrate 3000 is opened and, at time t11,immediately before the DC voltage is stopped, the cover is closed. Byclosing the cover when etching is not being performed, particlesoccurring because of peeling from the upper electrode 2200 or from theinside walls of the processing chamber 2000 are caught by the cover,thereby preventing the attachment of these particles to the substrate.

Furthermore, in addition to the above-noted configurations, it ispossible to use a configuration in which a detection means is providedthat detects that the cover 3600 has been placed in the closedcondition, the result of the detection by this detection means beingused to turn off the DC power supply 2400.

Twentieth Embodiment

The flow of cover operation timing in the twentieth embodiment of thepresent invention is shown in FIG. 25.

In addition to the seventeenth to the nineteenth embodiments, during theperiod of time from t15, immediately before the stopping of theapplication of the DC voltage, to the time t16, several seconds afterthe start of the introduction of the purging gas, a potential isimparted to the cover 3600. Particles that are generated immediatelyafter the stopping of application of the DC voltage fall toward and areattracted to the cover 3600. Particles that are generated after theintroduction of the purging gas follow the flow of the purging gas, andfall toward the exhaust port, so that they do not become attached to thesubstrate.

The material of the cover 3600 can be the same conductive material asthe processing chamber 2100 inner wall, this being for example analuminum alloy and, to reduce the number of particles that aregenerated, it can also have a metallic surface that is covered withaluminum oxide or silicon oxide.

Twenty-First Embodiment

The flow of cover operation timing in the twenty-first embodiment of thepresent invention is shown in FIG. 26.

In the cases of the eighteenth and nineteenth embodiments of the presentinvention, as shown in FIG. 23 and FIG. 24, it is possible to impart apotential to the cover from the time t17, at which the application ofthe DC voltage is stopped, until time t18, at which point the processedsubstrate has been completely transported to outside the processingchamber. Particles that are generated in the period from the timeimmediately after the stopping of application of the DC voltage to thetime the transporting port opens are collected by the cover, andtherefore do not become attached to the substrate.

Twenty-Second Embodiment

The flow of cover operation timing in the twenty-second embodiment ofthe present invention is shown in FIG. 27.

In the cases of the eighteenth and nineteenth embodiments of the presentinvention, as shown in FIG. 23 and FIG. 24, it is possible to impart apotential to the cover, from the time that the cover is started to beclosed until the time the cover is opened. By making the cover 3600 thesame potential as the lower processing electrode 2300 during theapplication of the DC voltage, there is no discharge between thesubstrate 3000 and the cover 3600, thereby enabling prevention of damageto the substrate and the generation of particles between the cover andthe substrate.

Then, after the application of the DC voltage is stopped, the coverpotential is either made equivalent to the self-bias potential, or apotential that has the same polarity as and an absolute value that isgreater than the self-bias value.

It is also possible to apply this embodiment to the seventeenthembodiment.

Twenty-Third Embodiment

FIG. 28 shows one typical operating cycle of a DC plasma processingapparatus generally used in a semiconductor device plant.

In the twenty-third embodiment of a DC plasma processing apparatus shownin FIG. 29, when the DC plasma processing is completed, it is known thatthe particles have a positive charge and, by making use of thisphenomenon, by imparting a negative potential to an electricallyconductive particle-removing electrode 11, particles are removed. Aslong as there is no influence on the DC plasma process, theparticle-removing electrode 11 can be any shape such as that of a sheetor grid.

The large number of falling particles that are generated at the instantthat the DC voltage is stopped are trapped by the particle-removingelectrode 11, thereby preventing their reaching the substrate 3000.

Twenty-Fourth Embodiment

FIG. 30 shows a DC etching apparatus into which a function has beenbuilt to trap particles, using an attachment-prevention shield.

In a semiconductor device manufacturing apparatus, anattachment-prevention shield 12 is often used to prevent the attachmentof sediments that occur during processing onto the chamber walls.

These attachment-prevention shields intentionally cause sediments to bedeposited onto these attachment-prevention shields 12, and by replacingthe attachment-prevention shields 12, it is possible to reduce thenumber of times the inside of the chamber needs to be cleaned.

The attachment-prevention shield 12 is often made of an electricallyconductive metal, the attachment-prevention shield 12 being keptelectrically insulated from the processing chamber, and when the etchingis completed, a negative potential is imparted to theattachment-prevention shield 12.

The large number of positively charged falling particles that aregenerated at the instant that the DC voltage is stopped are pulled in bythe negative potential on the attachment-prevention shield 12 andtrapped and ultimately are trapped on the wall of theattachment-prevention shield 12, thereby preventing their reaching thesubstrate 3000.

Twenty-Fifth Embodiment

FIG. 31 shows an etching apparatus into which a function has built totrap particles, using an electrically conductive grid 13.

Specifically, the grid 13 is installed so that it is electricallyinsulated from the processing chamber and, when the etching iscompleted, a negative potential is imparted to the grid 13.

The large number of positively charged particles that fall when the DCvoltage is stopped are pulled in by the negative potential of the grid13, and are ultimately trapped by this grid 13, so that they areprevented from reaching the substrate.

Twenty-Sixth Embodiment

FIG. 32 shows a DC plasma processing apparatus in which a gas exhaustport 14 is formed at the bottom of the processing chamber and iselectrically insulated from the chamber, thereby forcibly exhaustingparticles.

That is, in the above-noted particle-removing apparatus, when the DCplasma processing is completed, a negative potential is imparted to theexhaust port 14, the result being that the large number of positivelycharged particles that fall at the instant the DC voltage is stopped arepulled in toward the exhaust port 14, which has a negative potential,these particles being ultimately exhausted, so that they are preventedfrom reaching the substrate 3000.

Twenty-Seventh Embodiment

FIG. 33 shows an etching apparatus in which an electrically conductivegrid 13 is provided in proximity to the gas exhaust port 14, this gridserving to trap particles.

Specifically, the grid 13 is installed in front of the exhaust port 14so that it is electrically insulated with respect to the chamber, anegative potential being imparted to the grid 13 when DC plasmaprocessing is completed.

The large number of positively charged particles that fall at theinstant the DC voltage is stopped are pulled in toward the grid 13because of its negative potential, and are ultimately trapped by thegrid 13 or exhausted from the exhaust port 14, so that they areprevented from reaching the substrate 3000.

Twenty-Eighth Embodiment

FIG. 34 shows the twenty-eighth embodiment of the present invention.

In this embodiment, the electrically conductive grid 13 is installedbetween the upper electrode 2200 and the lower electrode 2300, and isplaced in an electrically floating condition. By doing this, during theprocess, that is during discharge, the grid 13 tracks to the potentialof the plasma, so that it is in the floating condition.

After the process is completed, the grid 13 is connected to a powersupply 4400, and a discharge is caused between the grid 13 and the upperelectrode 2200. When this is done, the power supply 4400 is notconnected to the lower electrode 2300.

Then, in this condition, the semiconductor substrate 3000 istransported. By doing this, particles remain trapped between the upperelectrode 2200 and the grid 13 and fly toward the area surrounding theplasma where they fall around the periphery thereof, so that they do notfall onto the substrate.

Twenty-Ninth Embodiment

FIG. 35 shows the twenty-ninth embodiment of the present invention.

In this embodiment, a plasma PZ is generated that is sufficiently largewith respect to the semiconductor substrate 3000. This plasma PZ isgenerated in accordance with the diameters of the upper electrode 2200and the lower electrode 2300 and, in the case of FIG. 35, this is aplasma that is generated to considerably outside the substrate 3000.

By doing this, so that the plasma PZ extends greatly beyond thesubstrate 3000, particles drop along the outer periphery of the plasmaPZ, thereby preventing them from falling onto the substrate 3000.

Thirtieth Embodiment

FIG. 36 shows the thirtieth embodiment of the present invention.

In this embodiment, a donut-shaped electrode 15 is installed over thelower electrode 2300 so as to surround the substrate 3000, a negativevoltage being applied to the electrode 15.

The timing of the application of the above-noted voltage is the timethat the process is completed and the time that the plasma power supplyis turned off.

By doing the above, positively charged particles are guided to theelectrode 15, thereby preventing them from falling onto the substrate3000.

Thirty-First Embodiment

FIG. 37 shows the thirty-first embodiment of the present invention.

In this embodiment, a laser apparatus is introduced for the purpose ofmonitoring the generation of particles. The location at which the laserlight is shined is the region under the upper electrode 2200. Byadopting this configuration, it is possible to detect at an early stageparticles that are trapped in the region near the plasma sheath.

Then, after the particles are detected, a negative voltage is applied tothe electrode 15, so as to collect the particles, preventing them fromfalling onto the substrate 3000.

Thirty-Second Embodiment

FIG. 38 shows the thirty-second embodiment of the present invention.

In this embodiment, gate valves 17 are installed on the side wall of theprocessing chamber near the upper electrode 2200, a vacuum pump or othersuch exhausting apparatus being connected to the outside thereof. Anelectrode 15 is installed in front of the gate valve 17, and a provisionis also made to apply a negative voltage to this electrode 15.

When the processing is completed and the voltage applied to the lowerelectrode 2300, is cut off, a negative voltage is applied to theelectrode 15. By doing this, particles are pulled toward the gate valve17. When this occurs, the gate valve 17 is opened, so that the particlesare exhausted, thereby preventing the particle from falling onto thesubstrate 3000.

As described in detail above, the present invention is capable ofreducing the particles that become attached to a substrate, and is aninvention that is based on the charged condition of the particles,enabling highly efficient prevention of attachment of particles.

What is claimed is:
 1. A particle-removing apparatus of a semiconductordevice manufacturing apparatus that comprises an etching processingchamber, a pair of processing electrodes formed by an upper electrodeand a lower electrode, which are installed within said processingchamber, and a susceptor that holds a substrate to be processed onto thetop of said lower electrode, a processing gas being introduced into saidetching processing chamber, a prescribed voltage being applied to saidprocessing electrodes, so as to generate a plasma of said gas, therebyprocessing the substrate on the susceptor, and a particle-removingelectrode for the purpose of removing particles being provided insidesaid processing chamber, said particle-removing electrode being directlyexposed to said plasma, whereby, after completion etching of saidsubstrate, a negative voltage is applied to said particle-removingelectrode, so that charged particles inside said processing chamber areguided to said particle-removing electrode and caused to be attachedthereto, thereby removing said particles.
 2. A particle-removingapparatus according to claim 1, wherein said particle-removing electrodeis provided between said upper electrode and said lower electrode.
 3. Aparticle-removing apparatus according to claim 1, further comprising anexhaust port disposed on a side wall of said etching chamber, in aregion in which said particle-removing electrode is provided.
 4. Aparticle-removing apparatus according to claim 1, wherein saidparticle-removing electrode is provided above said lower electrode in amanner that surrounds said substrate.
 5. A particle-removing apparatusaccording to claim 1, wherein said particle-removing electrode isprovided between said processing electrode and a side wall of saidprocessing chamber.
 6. A particle-removing apparatus according to claim5, wherein said particle-removing electrode is a attachment-preventingplate that prevents sediments from becoming attached to a wall surfaceof said processing chamber.
 7. A particle-removing apparatus accordingto claim 1, wherein said particle-removing electrode is provided withina gas exhaust port or said etching processing chamber or near saidexhaust port.
 8. A particle-removing apparatus according to claim 1,wherein said particle-removing electrode is electrically conductive andplanar in configuration.
 9. A particle-removing apparatus according toclaim 1, wherein said particle-removing electrode is an electricallyconductive grid-configured electrode.
 10. A particle-removing apparatusaccording to claim 1, wherein said negative voltage is applied aftercompletion of etching.
 11. A particle-removing apparatus according toclaim 1, wherein said negative voltage is applied during transporting ofsaid substrate.
 12. A particle-removing apparatus of a semiconductordevice manufacturing apparatus that comprises an etching processingchamber, a pair of processing electrodes formed by an upper electrodeand a lower electrode, which are installed within said processingchamber, and a susceptor that holds a substrate to be processed onto thetop of said lower electrode, wherein a processing gas being introducedinto said etching processing chamber, and a prescribed voltage beingapplied to said processing electrodes, so as to generate a plasma ofsaid gas, thereby processing the substrate on the susceptor, saidparticle-removing apparatus comprising a gas exhaust port of saidprocessing chamber, which is formed of an electrically conductivematerial, a negative voltage being applied to said electricallyconductive material, so as to remove charged particles within saidprocessing chamber.
 13. A particle-removing apparatus of a semiconductordevice manufacturing apparatus that comprises an etching processingchamber, a pair of processing electrodes formed by an upper electrodeand a lower electrode, which are installed within said processingchamber, and a susceptor that holds a substrate to be processed onto thetop of said lower electrode, wherein a processing gas being introducedinto said etching processing chamber, and a prescribed voltage beingapplied to said processing electrodes, so as to generate a plasma ofsaid gas, thereby processing the substrate on the susceptor, saidparticle-removing apparatus comprising an electrically conductivegrid-configured material for the purpose of particle removed, saidmaterial being dispersed between said upper and said lower electrode andbeing directly exposed to said plasma, and a negative voltage beingapplied to said grid-configured material, so as to remove chargedparticles from said processing chamber.
 14. A particle-removingapparatus of a semiconductor device manufacturing apparatus thatcomprises an etching processing chamber, a pair of processing electrodesformed by an upper electrode and a lower electrode, which are installedwithin said processing chamber, and a susceptor that holds a substrateto be processed onto the top of said lower electrode, a processing gasbeing introduced into said etching processing chamber, and a prescribedvoltage being applied to said processing electrodes, so as to generate aplasma of said gas, thereby processing the substrate on the susceptor,said particle-removing apparatus comprising a particle-removingelectrode for the purpose of removing particles, said particle-removingelectrode being disposed in a region near said substrate and beingdirectly exposed to said plasma, a negative voltage that has an absolutevalue that is larger than a self-bias voltage of said lower electrodebeing applied thereto, so as to prevent particles within said processingchamber from falling onto said substrate.
 15. A particle-removingapparatus of a semiconductor device manufacturing apparatus thatcomprises an etching processing chamber, a pair of processing electrodesformed by an upper electrode and a lower electrode, which are installedwithin said processing chamber, and a susceptor that holds a substrateto be processed onto the top of said lower electrode by an electrostaticchuck electrode, a processing gas being introduced into said etchingprocessing chamber, and a prescribed voltage being applied to saidprocessing electrodes, so as to generate a plasma of said gas, therebyprocessing the substrate on the susceptor, a constant negative biasvoltage being applied to said lower electrode, said bias voltage beingcaused to vary in the same manner as a bias voltage applied to theelectrostatic chuck electrode.
 16. A particle-removing apparatusaccording to any one of claim 1 through claim 15, further comprising alaser apparatus for the purpose of detecting the generation of saidparticles, light from said laser apparatus being shined in a region nearsaid upper electrode, and comprising a third control means for thepurpose of applying a negative voltage to said particle-removingelectrode, based on the results of said detection.
 17. Aparticle-removing apparatus of a semiconductor device manufacturingapparatus comprising: an etching processing chamber, a pair ofprocessing electrodes formed by an upper electrode and a lowerelectrode, which are installed within said processing chamber, and asusceptor that holds a substrate to be processed on a top of said lowerelectrode, a processing gas being introduced into said etchingprocessing chamber, a prescribed voltage being applied to saidprocessing electrodes, so as to generate a plasma of said gas, therebyprocessing said substrate on said susceptor, wherein a particle-removingelectrode for removing particles is provided near an exhaust portdisposed at a bottom of said etching processing chamber and beingdirectly exposed to said plasma, a negative voltage being applied tosaid particle-removing electrode, said exhaust port being formed of anelectrically conductive material with a negative voltage being appliedthereto.
 18. A particle-removing apparatus according to claim 17,wherein said negative voltage has an absolute value that is greater thana self-bias voltage of said lower electrode.
 19. A particle-removingapparatus of a semiconductor device manufacturing apparatus comprising:an etching processing chamber, a pair of processing electrodes formed byan upper electrode and a lower electrode, which are installed withinsaid processing chamber, and a susceptor that holds a substrate to beprocessed on a top of said lower electrode, a processing gas beingintroduced into said etching processing chamber, a prescribed voltagebeing applied to said processing electrodes, so as to generate a plasmaof said gas, thereby processing said substrate on said susceptor,wherein an exhaust port is provided at a bottom of said etchingprocessing chamber and said exhaust port is formed of an electricallyconductive material, a negative voltage being applied to said exhaustport.
 20. A particle-removing apparatus according to claim 19, whereinsaid negative voltage has an absolute value that is greater than aself-bias voltage of said lower electrode.
 21. A particle-removingapparatus of a semiconductor device manufacturing apparatus comprising:an etching processing chamber, a pair of processing electrodes formed byan upper electrode and a lower electrode, which are installed withinsaid processing chamber, and a susceptor that holds a substrate to beprocessed on a top of said lower electrode, a processing gas beingintroduced into said etching processing chamber, a prescribed voltagebeing applied to said processing electrodes, so as to generate a plasmaof said gas, thereby processing said substrate on said susceptor,wherein a particle-removing electrode for removing particles is providedwithin said processing chamber and being directly exposed to saidplasma, a negative voltage that has an absolute value that is greaterthan a self-bias voltage of said lower electrode, is applied to saidparticle-removing electrode.
 22. A particle-removing apparatus accordingto claim 21, wherein said particle-removing electrode is provided so asto cover said substrate.
 23. A particle-removing apparatus according toclaim 21, wherein said particle-removing electrode is provided on a topof said lower electrode and provided so as to surround said substrate.24. A particle-removing apparatus according to claim 21, wherein saidparticle-removing electrode is provided near an exhaust port disposed ata bottom of said etching processing chamber.
 25. A particle-removingapparatus according to claim 21, wherein said particle-removingelectrode is provided within an exhaust port disposed at a bottom ofsaid etching processing chamber.
 26. A particle-removing apparatusaccording to claim 21, wherein said negative voltage is applied aftercompletion of etching of said substrate.
 27. A particle-removingapparatus according to claim 21, wherein said negative voltage isapplied during transporting of said substrate.